Friday, September 27, 2013

Carrier Bag Scepticism

Cut to the haunting image of a sea turtle, thousands of miles away, struggling through the deep ocean waters as discarded plastic bags wrap themselves around its flippers and body.

These majestic animals are dying in alarming numbers because they mistake the flimsy translucent bags - which could in theory come from British supermarkets - for jellyfish, a key element of their diet.

The endangered Green Turtle provides a potent symbol of the deadly threat to wildlife and the blight on the natural world caused by throwaway plastic bags handed out free in their billions to shoppers. [Daily Mail, 27 February 2008]

Who can fail to be moved by the image conjured so vividly in those few sentences? Scourge of the oceans, destroyer of marine life and polluter of the eco-system, the carrier bag is everything that is wrong with our throwaway life styles. Only the most hard-hearted and selfish could say otherwise. Except that, as with many environmental scares and controversies, the reality is considerably more complex than these often simplistic narratives would indicate. Perhaps the case for the prosecution is not as strong, or as straightforward, as would first appear…

At first glance the case against the carrier bag seems self-evident. It is wasteful – the bags are throwaway by design. They use up resources – plastic carrier bags are made from oil and obviously use up energy in their manufacture. They pollute the environment – famously being a key ingredient of the ‘great Pacific garbage patch’, (or the Pacific Trash Vortex if your language tends to the dramatic) or the similarly described patch in the Atlantic. And finally, the great and the good have come out firmly against them – from hardened environmentalists to the BBC to the Daily Mail and Marks and Spencers. In fact, in some more environmentally conscious parts of the world, Wales for example, the carrier bag already incurs a surcharge – a guilt tax to nudge us towards greener alternatives.

Firstly let’s note that the carrier bag, an item that is both dull and yet comfortingly familiar, has been subtly rebranded by campaigners. It is now the single-use carrier bag. This simple renaming is charged with disapproval. In an age where recycling is an uncontested virtue, to point out that plastic carrier bags are ‘single use’ is to win the argument before it has even started. But the reality is that many people do not simply use a bag once and then discard it. This issue of whether they are used singly or multiply is an important one that we will return to later.

Putting aside the question of use versus reuse for the moment, what of the objection that the bags use up valuable oil-based raw materials? The truth is not quite so straightforward. Plastic carrier bags are made from high-density polyethylene (HDPE) – which is itself derived from ethylene, which in turn comes from ethane, a by-product of oil and gas refining. In the past ethane was simply burned off as waste. Today it’s considered a valuable by-product in part because it is a feedstock to ethylene and polyethylene to make…carrier bags.

But what about that garbage patch in the Pacific or the Atlantic? Even if carrier bags don’t use up precious resources, they’re still contributing to pollution, and most egregiously to the monstrous swirl of plastic trash that’s so huge it can be seen from space (allegedly). It has been covered by media outlets across the globe – for example the Daily Mail trumpeted that ‘Rubbish dump found floating in Pacific Ocean is twice the size of America’. Or perhaps you’d care for something a little different, like the ‘great Atlantic garbage patch’ that the BBC reported on with similar breathless prose?

Whether it’s the Pacific or the Atlantic the essential elements of the story are the same: huge amounts of plastic waste gets dumped into the ocean, it is sucked into complex currents (the North Pacific Gyre, for example) and pushed out into the deep oceans where it congregates and causes harm to marine life. Indeed, as we have seen, the threat to marine life was a central part of the Daily Mail’s litany of wrongs outlined in its ‘Banish The Bags’ campaign.

Recent research, however, suggests that the reality is not as dramatic as the more alarmist claims would have us believe. Firstly, just how big is this patch? According to Professor Angelique White, of the College of Oceanic and Atmospheric Sciences at Oregon State University, and a scientist who participated in one the few expeditions to research the patch in situ, the size has been grossly exaggerated. In her words:

…the plastic debris floating in the surface waters of the North Pacific could be corralled to produce a solid patch that is a small fraction of the state of Texas

But even that doesn’t give the correct impression because the patch is actually very dilute – it is made up of tiny particles of broken down (photodegraded) plastic. Again, Professor White is clear:

…a dilute soup of very small pieces of plastic that were largely invisible to the naked eye.

Mostly it’s not even possible to identify the source of the plastic, according to the recent Plastics At Sea research project:

In most cases it is impossible to know what kind of object the plastic pieces came from. The most recognizable pieces are fragments of fishing line and industrial resin pellets (the “raw material” of consumer plastic products).

The truth is, therefore, that we do not even know how much of the plastic in the oceans actually derives from carrier bags. There is evidence to suggest that far more dangerous to marine life are the debris and pollution from shipping. While the popular image may be that there are millions of carrier bags floating through the oceans and ensnaring or being ingested by marine life, the reality is that carrier bags photodegrade into tiny pieces of plastic that are a component of the ‘garbage’ patches. There is much research to do for sure, but the global emergency created by floating bags does not exist. An international research workshop on microplastics in the oceans was held at the University of Washington at the end of 2008, and it brought together leading researchers in a field that is still relatively under-researched. One of the sessions was on the impacts of plastics on the marine environment. As reported in the published proceedings:

Some connections were drawn between ingestion of microplastics and seabird death, but overall the impact on entire seabird populations is either unknown or not considered to be large enough to warrant further investigation at this time (Auman 2009; Mallory et al. 2006; van Franeker 2009). One presentation given in this session discussed the results of a laboratory study that surveyed the ability of several marine invertebrates to ingest microplastics. The lugworms, amphipods, barnacles, and mussels all were capable of ingesting and passing microplastics through their digestive systems, even though each has a different mode of feeding and particle selection (Browne et al. 2008; Thompson et al. 2004)… Data that conclusively demonstrate negative impacts of microplastics on the marine environment are not available.

Perhaps then, the marine situation is not as dire or as clear-cut as has been suggested by green campaigners and their corporate allies. But even so, surely carrier bags have a negative impact in terms of carbon emissions and global warming? Not according to the Environment Agency, which studied precisely that question and came up with some surprising (and to many environmentalists, disappointing) conclusions:

The environmental impact of all types of carrier bag is dominated by resource use and production stages. Transport, secondary packaging and end-of-life management generally have a minimal influence on their performance. Whatever type of bag is used, the key to reducing the impacts is to reuse it as many times as possible and where reuse for shopping is not practicable, other reuse, e.g. to replace bin liners, is beneficial.

The reuse of conventional HDPE and other lightweight carrier bags for shopping and/or as bin-liners is pivotal to their environmental performance and reuse as bin liners produces greater benefits than recycling bags. Paper, long-life, non-woven polypropylene and cotton bags should be reused at least 3, 4, 11 and 131 times respectively to ensure that they have lower global warming potential than conventional HDPE carrier bags that are not reused.

In other words this – a simple case of increasing re-use – is the key to further mitigating the environmental impact of carrier bags, which are, as we have seen, far less dramatic than the headlines would have us believe. Far from being the villain, the carrier bag may actually be the hero of the piece. Indeed the same report showed that if carrier bags are used for shopping three times, then the paper, long-life, non-woven polypropylene and cotton bags should be reused at least 9, 12, 33 and 393 times to have a lower global warming potential.

Do we know that carrier bags are actually re-used, or are they really ‘single use’ as the relabelling would have it? A number of surveys on the subject have been published, and the findings are fairly consistent. For example a DEFRA commissioned poll in 2000 found that 80% of people re-used carrier bags. A more recent report for Lancashire County Council found that 92% of people engaged in re-use, with the most popular uses being rubbish collection, using as a bin liner or for shopping – with a host of other uses, such as for collecting up pet waste, also being listed.

So here too we find that the perception of the carrier bag as a contributor to global warming is over-stated. Yet it is, for example, the first of the three reasons given for the introduction of a carrier bag charge in Wales – the other two being:

…to increase environmental awareness; and help us all adopt more sustainable lifestyles.

If the rationale for banning carrier bags is so lacking in merit, then the question has to be asked: why subject consumers to the inconvenience of the alternatives? And the answer is that it is the inconvenience that is precisely the point.

Like the stone in the shoe that reminds the devout Christian of Christ’s suffering with every step, a ban on carrier bags is a reminder to the consumer of the Earth's suffering with every shop. What is more, this irritant is there at the point of sale, an inconvenience at the check-out, a reminder of the sins we are committing against Gaia. If we like we can chose to pay a sin tax and buy a carrier (in those shops that have imposed a charge on bags), or we can affirm our faith by using a supposedly Gaia-friendly long-life or paper bag, or else we just put up with the hassle of walking out with arms laden with goods (a subsidiary lesson being that perhaps we should buy less next time).

In any case, we have been reminded both of our relationship to the environment and of the changes being wrought to right the wrongs that we have inflicted with our decadent and profligate lifestyles.

The campaign to ban carrier bags is important because it is so unimportant. Like wind-farms or bio-fuels, banning carrier-bags is about gesture more than it is about outcome. It is light on evidence, posits environmental disaster, proposes solutions that involve cost and inconvenience and is, therefore, a classic environmental scare that does not stand up well to scrutiny.

Perhaps the cause of carrier bag scepticism will not incite the fury that climate change scepticism generates, but it’s a worthy cause for environmental heretics to adopt all the same.

1 comment:

bilbaoboy said...

The penultimate paragraph sums it all up.

Leftish greenery is about feeling good, or not feeling guilty.

Evidence, data, results don't enter into it.

It is a substitute for thought, analysis and reality